包装技术基础5.pptxVIP

Lesson 5 Metal Containers 第5课 金属容器 Background Steel is one of the older packaging materials.- Originally used for round, square, and rectangular boxes and canisters. - The old-fashioned appearance of a fabricated metal box is effectively used to create nostalgia for specialty and gift-type containers. - Sanitary food can, hand-soldered cylindrical metal cans started in the early l800s.- Metal cans’ advantages: Background being relatively inexpensive capable of being thermally processedrigid easy to process on high-speed linesreadily recyclabletotal barrier to gas and lightan important means of delivering a shelf-stable product - Food cans: three-piece construction (Figure 5.1). Background Figure 5.1 Three-piece (left) and two-piece(right) can construction Background Shallow drawn containers with friction or slip covers- Two-piece shallow drawn cans with double-seamed (folded) ends - Two-piece cans (Figure 5.1). reduced metal usageimproved appearanceelimination of a possible leakage locationmore elaborate tooling required - Deeper draws and multiple draws and draw-and-iron process -Impact-extrusion: tin, lead, and Al; collapsible tubes (nearly Al); heavier gauge aluminum extrusions used for pressurized aerosol containers Common Metal Container Shapes Three-piece steel sanitary food cans. ·Aerosol cans, made by two methods: (1) Three-piece steel cans with a welded body and two ends, and (2) one-piece, impact-extruded aluminum cans necked-in to accept the valve cup. ·Steel or aluminum two-piece drawn-and-ironed beverage cans. ·Two-piece steel or aluminum cans by drawing or by draw and redraw. Full-opening, ring pull-top cans Double-seamed, conventional-top cans ·Cans with hinged lids, usually steel Common Metal Container Shapes Flat round cans of drawn steel or aluminum with slipcovers (Figure 5.2) ·Three-piece steel or aluminum ovals, typically fitted with a dispensing spout (Figure 5.2) ·Traditional pear-shaped, three-piece steel ham can